Preliminary studies conducted by the University of Minnesota Chemical Dependency Treatment Program provide evidence that carbamazepine may be beneficial in the treatment of cocaine abuse. The proposed project is an attempt to examine the effectiveness of carbamazepine in a more rigorously controlled experimental setting. The following research questions will be addressed: (1) Is carbamazepine an effective intervention in the treatment of cocaine use and dependence? (2) Does carbamazepine reduce the craving associated with cocaine use? (3) What is the optimal serum carbamazepine concentration range for the treatment of cocaine abusers? (4) Do psychiatric, psychosocial and drug history factors mitigate the effects of carbamazepine? (5) Is carbamazepine equally effective for intravenous and non-intravenous cocaine users? (6) Does carbamazepine enhance the effectiveness of existing treatment strategies? The proposed project is a 12-week randomized double-blind placebo controlled study to be performed in conjunction with the existing outpatient treatment program at the University of Minnesota Chemical Dependency Treatment Program. Two parallel outpatient groups of subjects each will be enrolled during a 16 month period: 75 IV drug users and 75 crack smokers. Patients will be screened using a clinical diagnostic structured interview, medical evaluations (including a physical examination and EKG) and laboratory assessment. Patients enrolled into the study will be randomly assigned to one of 3 dose levels: 00 mg (placebo), 400 mg, or 800 mg. Patients will report for 12 weekly visits during which urine and blood samples will be collected, clinical and self-report instruments completed, side effects monitored, and weekly supplies of medication dispensed. Patients will be contacted 12 months after completion of the double-blind study to examine issues of long-term safety, efficacy and outcome. The major outcome variable for the proposed study is cocaine use as measured by self-report and confirmed by weekly urinalysis. Other outcome variables include other drug use (measured by self-report and urinalysis), subjective improvement, cocaine craving, depression, and completion of treatment. Analyses will focus on the relationship between serum carbamazepine levels and outcome variables. The research will provide information as to the effectiveness and feasibility of carbamazepine as an adjunct to traditional treatment activities.